下列复数① sqrt[4](6)(cos (pi)/(8)+i sin (pi)/(8));② sqrt[4](6)(cos (pi)/(8)-i sin (pi)/(8));③ sqrt[4](6)(cos (9pi)/(8)+i sin (9pi)/(8));④ sqrt[4](6)(cos (9pi)/(8)-i sin (9pi)/(8)).为 (sqrt(3)+sqrt(3)i)^(1)/(2) 的根的是 ( )

sqrt (2)pi :2 C. sqrt (2)pi :4 D. sqrt (2)pi :8

=-sqrt (2)(sin dfrac (pi )(6)+icos dfrac (pi )(6))的指数表达式为（ ）。A =-sqr

sqrt (2)pi -|||-C. dfrac (sqrt {2pi )}(4)-|||-D. dfrac (sqrt {2pi )}(8)

(B) sqrt (dfrac {1cos theta )(g)} _ (C) pi sqrt (dfrac {1)(8)} . (D) pi sqrt (df

11 单选 -|||-lim _(xarrow {pi )_(+)}dfrac (sqrt {1+cos x)}(sin x)= ()-|||-○

设 M=int_(-(pi)/(2))^(pi)/(2) (sin x)/(1+x^2) cos^4 x dx，N=int_(-(pi)/(2))^(pi)/(

(15)int_(-(pi)/(2))^(pi)/(2)sqrt(cos x-cos^3)xdx;(15)$\int_{-\frac{\pi}{2}}^{\fr

dfrac ({mu )_(0)I}(pi R)(dfrac (1)(2)+dfrac (pi )(6))-|||-dfrac ({mu )_(0)I}(pi

dfrac (2pi )(sqrt {3)} D. dfrac (pi )(6)

dfrac (2pi )(sqrt {3)}-|||-D. dfrac (pi )(6)